FPGAs--SRAM and Antifuse
Field programmable gate arrays (FPGAs) comprise programmable logic blocks and a programmable interconnect structure for interconnecting the blocks. The logic blocks are programmed to perform a desired function and the interconnect structure comprises wiring segments which may be interconnected to connect the logic blocks together as desired. Some interconnect structures are interconnected by turning on transistors which interconnect the wiring segments. Others are interconnected by programming antifuses which interconnect the wiring segments. Antifuse programming is achieved by applying sufficiently different voltages to the wiring segments which contact the two terminals of the antifuse to cause current to pass through the antifuse and cause the antifuse to become permanently conductive.